Manufacture of vulcanized fiber



Patented Jan. .22,

UNITED STATES PATENT OFFICE In the manufacture of been customary to treat MANUFACTURE or John K. Anthony, Cleveland signor to Horace B.

No Drawing. Application Serial No. 525,0

3 Claims.

vulcanized fiber, it has cellulose sheets with a hydrating agent, as zinc chloride or sulphuric acid, and then ply the 5 up the thickness desired,

out the hydrating agent.

sheets together to build and subsequently wash This latter operation is tedious, since the hydrating agent on the interior of the mass must be removed by osmotic action in the washing bath, and this requires much time in the case of thicker stock even months of continued washing. All this not only adds to the extent of plant equipment in the washing department, but also ties up a large stock of material in ingly a fundamental lar importance.

desideratum and of particu- To the accomplishment of the foregoing and related ends, the inventi on, then, comprises the features hereinafter fully described, and particularly pointed out scription setting in the claims, the following deforth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In proceeding in accordance with the invention, cellulose, conveniently in sheet form, usually as felted out in paper-like condition, is subjected to the action of a hydrating agent, as zinc chloride, zinc iodide, sulphuric acid, etc. Most usually, a zinc chloride solution is of rather high concentration 1%., or slightly more or desirable, this being for instance about less, in accordance with temperatures and particular character of product desired. The cellulose sheet, in one or more plies is fed through a bath of such hydrating agent, at a rate of travel to tion of, for example, 3 to 10 give a treating acmlnutes, depending upon the thickness of the sheet, and the concentration of the bath.

bath, the sheet material plus solution being elimin instance, to awater-wash this may be of a charac material passes therethr From the hydrating is then conducted, surated by squeeze-rolls for ing bath. Conveniently, ter such that the sheet ough in zig-zag course,

guided by suitable rollers, and preferably, the

wash-water is directed co rality of successive vats unter-currently. Aplumay be thus employed.

vULoANizEo FIBER Cleveland, Ohio March 24, 1931,

Fay,

Heights, Ohio, as-

After washing for several hours, the exact time depending upon'the the concentration of the sheet material is sidual hydrating agent.

thickness of the sheet, and

the original treating bath, sufiiciently freed from re- Surplus water is then 5 eliminated. The sheet material may be, in fact, quite largely dried, although it is advisably not dried to such a complete extent as to cockle. Freed of surplus water, the sheet material is then plied together with interposed material causing adhesion. This may 10 be provided, for instance,

by passing the sheet-stock through a cuproammonium solution, made by dissolving copper hydrate in ammonia, or by dissolving metallic copper in'the presence of air, in ammonia. More or less concentration of the ammonia is desirable,

depending upon the water remains in the sheet extent to which residual -stock. By passing the stock through the cupro-ammonium bath and then plying together, the product may be built up to such thickness as case. Drying is advis 20 desired in any particular ably carried out under tension or pressure, to insure smoothness of product. Among other convenient bonding agents, are

such materials as prcteinous agents, shellac in alcoholic solution, other resins, artificial resinoids such as phenol-aldehyde condensation products, and the like.

The latter may be applied as thinned by a solvent or cutting agent, for

instance ethyl alcohol with the commoner methanol being feasible With or artificial resinoids.

any such bonding agents, the vulcanized-fiber sheet material as coming from the washing and surplus-water eliminating stage, is simply passed through a bath of such bonding material, and is plied together to the desired thickness, desirably under tension or pressure.

be applied, particularl resin binders.

ishing pressing like is advisable.

and dried, Heat may y with the phenol-aldehyde In some cases, a further final finin a heated platen press or the In such manner, the vulcanized fiber product may be formed to any desired thickness, and irrespective ofthe thickness, it is seen that the residual zinc chloride or other hydrating agent can be completely washed out, thereby affording a staple and durable thickness. Moreover,

product irrespective of its since the washing is performed on unit-thickness material, the operation proceeds rapidly, and

requires no more time for products ultimately made of greater thickness.

Furthermore, it will heretofore vulcanized to the objection of h being inherently wate be noticed that whereas fiber has always been open ydroseopicity, the material r-attracting, in accordance I I 5 canized fiber product may 10 tures stated in any with-the present process where it is bonded by an extraneous bonding agent, water-proof materials may be so employed, as indicated in some of the above instances, and a water-resistant vulbe had in one simple and direct operation.

Other modes of applying the principle of the invention may be employed, change being made as 4 described, provided the teaor the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinct- 1y claim as my invention:

regards the details i. Vmcanized fiber bonded while containin disseminating water, by a water-borne agent which is water-insoluble as finally dehydrated.

2. Vulcanized fiber 'havinz initial hydratin agent eliminated and being bonded together by an extrinsic initially wate -soluble water-proof agent applied while the fiber contains disseminatand virhile the fiber contains with a strong cuproam- JOHN K. ANTHONY] amhavin initial hydratin 

